Jim,
According to this
GMC Engine casting number resource, your casting # 6107328 indicates it's a 1953-54 "248" engine.
An original engine for your 1941 would have a block casting number of "6107326" and would have been a "228", not a "248".
I couldn't find info on the "Stamped pad" number you provided. An original stamping would have started with "248" followed by a serial number according to previous posts
like this one.
Am sure fellow Bolters with more GMC knowledge will be along as they can to add info or ask further questions to help identify what you have.
Good luck in your search.
Dan
